The present disclosure is generally related to air filtering systems. The present disclosure is more particularly related to a yoke, filter and cover apparatus and a method of using a yoke, filter and cover apparatus for an air filtering system.
Many industries often encounter particulate matter suspended in the atmosphere. In some industries, this particulate matter is a valuable product, for example, starch; it would be beneficial if these suspended particulate could be recovered and reintroduced into the process. For other industries, such as metal or wood working, the particulate matter may be simply dust; it is desirable to remove dust particles from the air in order to provide a clean working environment.
Systems for cleaning an air or other gas stream laden with particulate matter include air filter assemblies that have filter elements disposed in a housing. The filter element may be a bag or sock of a suitable fabric or pleated paper. The gas stream, contaminated with particulate, typically is passed through the housing so that the particulate are captured and retained by the filter element. Cleaning is accomplished by periodically pulsing a brief jet of pressurized air into the interior of the filter element to reverse the air flow through the filter element, causing the collected contaminants to be collected . Such air filter assemblies are disclosed in, for example, U.S. Pat. No. 4,218,227 (Frey) and U.S. Pat. No. 4,395,269 (Schuler), which patents are hereby incorporated by reference.
Cylindrical filter elements are usually used in an air filter assembly to process dust particles from an air stream. In a standard design of air filter assembly, an air filter assembly has a clean air chamber and a dirty air chamber. The two chambers are separated by a sheet metal, commonly referred to as a tube sheet. The tube sheet has a number of openings from which cylindrical filters are aligned. The filters suspend downwardly with or without an angle from the tube sheet openings into the dirty air chamber. Particulate-laden air is introduced into the dirty air chamber, and the particulates collect onto the filter. The filtered air passes through the filters to the interior of the filters, and upwardly out through the openings in the tube sheet into the clean air chamber. From the clean air chamber, the cleaned air is exhausted into the environment, or recirculated for other uses. For example, U.S. Pat. Nos. 4,424,070 (Robinson), 4,436,536 (Robinson), 4,443,237 (Ulvestad), 4,445,915 (Robinson), 5,207,812 (Tronto et al.), 4,954,255 (Muller et al.), 5,222,488 (Forsgren), and 5,211,846 (Kott et al.) are prior art examples of prior art cylindrical filter elements of the pleated cartridge type.
Any particular filter assembly can have multiple filter constructions. The filter elements of a filter construction are supported by a frame or yoke which is attached to the tube sheet. The end of the filter is sealed with an access cover which is secured to the end of the yoke opposite the tube sheet.
It is periodically necessary to access the filter elements to determine whether maintenance or replacement of the filter elements is necessary. The replacement of used filter elements is a process that requires opening of the access cover, removal of the filter elements, placement of different filter elements on the yoke, and replacement of the cover in such a way to ensure the proper amount of tightening of the cover onto the filter element(s). There are typically many covers on a housing corresponding with the number of filter constructions in the filter assembly (e.g., 32 covers for 32 filter constructions in a single housing) and the above process must be performed for each cover.
Conventionally, the cover is attached to the yoke by a threaded aperture in the cover receiving a bolt attached to the plate on the yoke. See for example, U.S. Pat. No. 4,395,269. With this conventional design, it is difficult and cumbersome to locate the bolt in the threaded hole. Therefore, the process of accessing the filter is a time consuming process. Furthermore, there is no positive way to keep the cover on after totally loosening the threaded portions and the cover can fall to the ground if not securely held by the operator. It is also difficult to avoid over compressing the filters. The operator must be very careful to screw the cover onto the filter to just the proper tightness to avoid damaging the filters.
Oftentimes it is desirable to utilize filters that are not circular in cross section. For example, filters having an oval cross section are sometimes used. In filter constructions having multiple stacked filter elements, it is necessary to align non-circular cross section filter elements relative to one another. Without such alignment, the seal between adjacent filter elements may be broken. Conventionally, the alignment of adjacent filter elements is attempted by carefully sliding the filter elements onto the yoke in an aligned state. However, the filter elements often shift or rotate slightly on the yoke before the cover is tightened down.
The construction and arrangement of the disclosed filter apparatus helps to overcome the problems of the prior art. In particular, the disclosure provides a filter construction having a yoke with a keeper on one end. A filter having an opening is supported by the yoke. The cover for sealing the opening in the filter includes a plate for covering the opening, a tightening member connected to the plate, and a catch having a first end movably connected to the tightening member and a second end configured to engage the keeper. The plate is sealed against the opening by operating the tightening member to reduce the distance between the plate and the catch while the catch and keeper are engaged.
The disclosure also provides an air filter assembly for removing particulate matter from an incoming dirty air stream. The assembly includes a housing having an inlet, an outlet, a dirty air chamber and a clean air chamber and a first filter construction as provided above positioned in the dirty air chamber.
A method of accessing an air filter in an air filter assembly is also provided.